System and method for electrical circuit monitoring

ABSTRACT

Disclosed is a system and method for monitoring a characteristic of an environment of an electronic device. The electronic device may include a printed circuit board and a component. A sensor is placed on the printed circuit board, and may be between the component and the board, and connects to a monitor, or detector. An end user device may be used to store, assess, display and understand the data received from the sensor through the monitor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Non-Provisional patent application claims the benefit of the U.S.Non-Provisional application Ser. No. 15/170,710, entitled, “System andMethod for Electrical Circuit Monitoring”, which was filed with the U.S.Patent Office on Jun. 1, 2016, and claims the benefit of U.S.Provisional Patent Application No. 62/149,100, entitled, Method ofMonitoring Changes in Electrical Characteristics of a Circuit AssemblyDue to Contamination in Real Time, filed Apr. 17, 2015, both of whichare specifically incorporated herein by reference for all that theydisclose and teach.

BACKGROUND

Electronics, including semiconductors and hard disk drives, requireextremely high levels of performance. Even a minor lapse in quality orenvironmental conditions can result in severe operating variances.Environment conditions within which electronics operate, and aremanufactured, can vary widely. Reliable measurements and data toproperly utilize tools, such as electronic equipment, may be criticalfor certain fields, such as medical fields.

BRIEF SUMMARY OF THE INVENTION

An embodiment of the invention may therefore comprise a system formonitoring a characteristic of an environment of an electronic devicecomprising a printed circuit board and at least one component, thesystem comprising a sensor coupled to one of the component and theprinted circuit board, wherein the sensor provides a response to atleast one element in the environment, a detector connected to thesensor, wherein the detector comprises a device enabled to monitor datafrom the sensor.

An embodiment of the invention may further comprise a method ofmonitoring a characteristic of an environment of an electronic devicecomprising a printed circuit board and at least one component, themethod comprising placing a sensor on the printed circuit board,connecting a detector to the sensor, and connecting the detector to anend user device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an on circuit monitor from the underside view of a chip.

FIG. 2 show an on circuit monitor from the top side of a chip.

FIG. 3 shows an on board chemical sensor.

FIG. 4 shows an ion selective electrode on a printed circuit board.

FIG. 5 shows an on board gas sensor.

FIG. 6 shows an on chip gas sensor.

FIG. 7a shows an impedance sensing configuration.

FIG. 7b shows typical usage of an impedance sensing configuration.

FIG. 8a shows a capacitance sensing configuration.

FIG. 8b shows typical usage of capacitance sensing configuration.

FIG. 9a shows a voltage sensing configuration.

FIG. 9b shows typical usage of a voltage sensing configuration.

FIG. 10a shows a pressure sensing configuration.

FIG. 10b shows typical usage of a pressure sensing configuration.

FIG. 11a shows a humidity sensing configuration.

FIG. 11b shows typical usage of a humidity sensing configuration.

FIG. 12a shows an accelerometer configuration.

FIG. 12b shows typical usage of an accelerometer configuration.

FIG. 13a shows a strain-gauge sensing configuration.

FIG. 13b shows typical of a strain-gauge sensing configuration.

FIG. 14a shows a temperature sensing configuration.

FIG. 14b shows typical usage of a temperature sensing configuration.

FIG. 15a shows a radiation sensing configuration.

FIG. 15b shows typical usage of a radiation sensing configuration.

FIG. 16a shows a magnetic-field sensing configuration.

FIG. 16b shows a typical usage of a magnetic-field sensingconfiguration.

DETAILED DESCRIPTION OF THE INVENTION

Monitoring of electronic circuit assemblies may prevent untimelyfailure. Embodiments of the invention comprise a method and apparatusfor monitoring, in real time, changes in electrical characteristicswhich may be due to contamination of a circuit assembly either duringproduction, which may lead to failure. This monitoring may also beperformed when the circuit is in an end use environment, such as whenthe circuit is in the field. A field environment may be any environment,such as an outdoor environment, an indoor environment, or an environmentthat is internal, such as internal to a human body. In an example wherethe circuit is used internally to a human body, the invention may be anelectronic health monitor that monitors potentially critical circuitsand hardware for contamination that may lead to failure conditions. Themonitoring may result in user alerts, or alerts to operators or servicetechnicians. As a result of the alert, corrective actions may beperformed by such technicians, or by doctors in the case of anelectronic health monitor.

While real time monitoring and evaluation of effects on components iscontemplated, it is also contemplated that a monitor or detector, or anend use device, as explained below, date/time stamp data from a sensorin order that changes in the environment or characteristics related tothe environment be correlated to events.

Embodiments of the invention provide monitoring of integrated circuits,and other electronics, comprising sensors, computational devices, andancillary supporting electronics. Characteristics of electronics aremonitored, for example, in real rime and may be used to inform decisionmaking elements regarding any related risks and any related reliabilityas the monitoring may relate to possible failure modes. Other modesrelated to reliability, such as modes where performance is impacted orother measurements or influenced but where failure is not necessarilyresultant may be impacted. For instance, it may be chemicalcontamination that causes the degradation or failure.

While there are many non-electrochemical failure modes, electrochemicalmodes, for purposes of this embodiment, are defined modes caused by theimpact of any chemical or other contaminant, on an electrical circuit.The effects of such contamination may be measured through sensingchanges in electrical characteristics of a device such as an integratedcircuit. In order to achieve high reliability, the device in questionshould be clean from contaminates that would negatively impact thedevice, such as ionic contamination or contamination that would inducecorrosion or undesirable electrochemical reactions. Cleanliness in thiscontext may be defined as the absence of contamination on a circuitboard. Contaminations may be under components on the board and may causefailure or degradation of the device. In particular, cleanliness is thelack of ionic species or electrochemically active species on the board.It is understood that cleanliness is not limited to any particularsource, or chemical identity. Rather, contaminations, or physicalimperfections, relate to those that impact the circuit with particularfocus on the electrical impact, such as leakage current, dielectriclosses, parasitic capacitance, and by electrochemical impacts, such asgalvanic corrosion, dendritic growth, and electrochemical migration.Embodiments of this invention may provide an on board, or on componentsensor or device or system, enabled to gather data and manipulate thatdata into a decision point. The ability to gather data on thereliability of a device or a subsystem of the device may result in lessdowntime or in life saving decisions or actions. Embodiments of thisinvention provide a device and system capable of monitoring theelectronic assets for electrical performance against changes in itsworking environment, specifically on board cleanliness or physicalintegrity, and the changes over time on the board and under components.

The location of contaminations may also be important, as well as thetype of contamination. Residue pooled under a component may still beactive and ionic in nature. Pockets of contamination may be influencedby flux type, placement, wash characteristics, solder paste volume, PCBcleanliness and component type contamination. Accordingly, it can beseen that cleanliness and contamination is a “multi-variable” issue.

There may also be a wide variety of contamination sources. Contaminationsources may include fabrication residues on components, plating saltsand uncured solder mask on PCBs, flux residues, material handling fromhuman induced solvents body oils and organic matter, processingequipment, cleaning machine effectiveness, unique non-standard processesand martials, touch up and rework operations. There may also be othercontamination sources or causes not listed. The embodiments of theinvention are not limited to any particular contamination or cause, orlist of contaminations or causes. Those skilled in the art willunderstand the wide variety of contaminations and causes as well as thatthere may be other, unknown, contaminations or causes. Any and allcontaminations or causes may cause problems or degradations due tointermittent connections, corrosion, electrical shorts or arcing, forexample. These effects can negatively impact device functionality andend user requirements. In certain instances, these effects maycompromise national security or place people's lives at risk. Even onproducts that are not life critical or related to national security,uninterrupted service is often not tolerated by end users. Business maybe lost when products do not provide long term reliability.

As noted above, contamination on electronics, such as printed Circuitboards (PCB) is a concern for the reliability of the entire assembly orproduct that contains the electronics. While many consumer electronicsapplications may not be concerned with the reliability of electronics,particularly long term reliability, there are many industries, such asthe military, medical, capital equipment, aerospace, industrial, and oilexploration industries, for example, where failure of electronics isconsidered unacceptable, and extremely costly. This is primarily due tothe risk of loss of life incidents, or an expensive or lengthy period ofinoperability of the equipment leading to a large unexpected cost, or inaerospace applications, such as satellites repairing faulty electronicsis not an option. Further, knowledge of contamination on electronics canallow a manufacturer of the electronics, or the seller of the items, tomake business decisions based on projected life expectancy of theproduct.

There may be many sensors that can be used to gather data on differentcontaminates or changes in electrical parameters. Examples of sensorsthat may be used with the invention, either on the board or on thecircuit, include electrical characteristic sensors (resistance, current,voltage, impedance, reactance, dielectric constant and radio frequencycharacteristic sensors), environmental/meteorological sensors(temperature, atmospheric pressure, humidity, light, air flow,condensation sensors), chemical sensors (ion selective electrodes,poteniostatic, electrochemical cells, voltammetry, chemical selectivefield effect transistors, electrochemical sensors), gas sensors, andphysical sensors (stress, strain, pressure sensors).

Resistance sensors may be either on board or on circuit and allow formeasurement of resistance between two electrodes. Depending on theresistance measured, the presence of contaminants can be assessed eitherunderneath the components or on the board surface.

Capacitive sensors may be on board or on the circuit and allow formeasurement of the capacitance between two electrodes. Depending on thecapacitance measured, the presence of contamination underneathcomponents or on the board surface can be assessed. For instance, inmany component types and circuit types, capacitance must be relativelylow for proper functioning. Measurements of capacitance beyond a certainthreshold may indicate the presence of contaminants.

Impedance sensors may be on board or on the circuit and may provideindications of a combination of resistance and capacitance.Incorporation of the frequency domain may provide a more detailedassessment of the presence of contaminants on the circuit board orunderneath a component. This may be useful, for example, in the contextof high speed electronics and radio frequency electronics.

Voltage sensors may be on board or on the circuit and allow for themeasurement of voltage leakage between electrodes. Depending on thevoltage leakage found, the presence of contaminants may be assessedunderneath components or on the board.

Current sensors may be on board or on the circuit and allow for themeasurement of temperature using a thermistor or other type oftemperature sensor between electrodes. The temperature determined on theboard or under a component may aid in determining the lifespan ofsemiconductors such as diodes, transistors, and more complicatedintegrated circuits (IC). Monitoring for changes underneath a componentallows for the analysis of IC aging as a function of temperature changesovertime.

Humidity sensors may be on board or on the circuit and allow for themeasurement of humidity measured by the electrodes. Humidity sensing mayaid in assessing moisture absorption possibilities as that may relate toactivation and movement of ions underneath a device or on the board.

Chemical sensors may be on board or on the circuit and may allow for oneor more chemical type sensors. Chemical sensors allow for highlyselective monitoring of chemical species, such as an immunoassay, or anon-selective technique such as an Oxidation Reduction Potential (ORP)electrode, which responds to many different electrochemically activespecies. Some chemical sensors may be able to be miniaturized so thatthey may be placed underneath components, use no reagents and thuseliminate maintenance, are solid stat or use gel materials to avoidcontamination of a circuit, or may output a signal that is easilyconverted into an electronic signal. Chemical sensors include, but arenot limited to, ion select electrodes (ISE) including pH electrodes,coulometry, potentiometric, voltammetry, amperometry, and chemicalselective field effect transistors. The specific environment that adevice resides in may determine what particular chemical sensors typesare used for the monitoring and what chemical species are monitored. Forinstance, if the electronics to be monitored are in a fluid environmentwhere certain pH levels may cause excessive corrosion to the device, thepH electrode may be used and would single that there is potential issueswith the monitored device. The electronic assembly would detect changesin the local environment and the changes can be correlated to thereliability of the electronic device. The correlation may be recorded asaccumulated damage to the device and use an actuarial type table todetermine a projected lifetime, for example.

Gas sensors may be on board or on the circuit and allow detection of theinflux of gases underneath components that may either directly degradean assembly or may allow electrochemical reactions to occur which maylead to further degradation or failure. Examples of such gases areacidic, basic, sulfurous, or corrosive.

Radiation sensors may be on board or on the circuit and allow for themeasurement of radiation. Such radiation may be alpha, beta, gamma orX-ray radiation. Depending on the amount of radioactive measurementsfound, assessment can be made of the impact of the radiation.Alternatively to distributing discrete sensors on the circuit assembly,radiation sensors may be placed underneath specific components that areradiation sensitive, such as the memory and the microprocessor. Thiswill allow a determination of radiation exposure to particularcomponents.

Physical sensors may be on board or on the circuit and allow for themeasurement of physical stresses such as stress, strain, and pressure ata specific component. Physical sensing provides reliability assessmentfor electronics due to its ability to discern changes in stress orstrain on components. Physical sensing allows for an assessment ofphysical damage, abuse, changes in temperature, or even electrochemicalprocesses that result in a change in operating conditions relating todegradation or failure.

Sensors may be on board or on a component or under a component and maybe wired or wireless depending on the desired use. The diversity of howand where a sensor is used allows for a number of different applicationsand environmental contexts.

Sensors may provide raw data streams that are manipulable into usefuldata through a variety of different electronic, or otherwise, devices.Such devices include, but are not limited to microprocessors,analog-to-digital converters and other well know devices known to thoseskilled in the art.

In embodiments of the invention, electrically conductive traces thatserve as sensors may preferably be located under or on components. Thetraces may be connected to a monitoring circuit. The monitoring circuitmay then be used to alert operators, or system features, of potentialdevice functional degradation or failure.

Embodiments of the invention may use conductive material, or traces, asa sensor and circuitry to monitor certain electrical characteristics ofkey areas of the electronic assembly. As noted above, the electricalcharacteristics that may be monitored include, but are not limited to:electrical resistance, capacitance, inductance, voltage, current,dielectric constant, and/or temperature. Temperature, while ameteorological concept, is listed as an electrical characteristic due tothe fact that it may be measured electrically, such as by using athermistor. Those skilled in the art will recognize that a thermistormay change resistance based on temperature. A thermocouple may alsomeasure temperature by monitoring voltage changes. It is understood thattemperature is a useful predictor in regard to the life time oftransistors, diodes, IC and other electrical components that may be usedon a circuit board.

All of the sensors mentioned above, as well as others, may be used fordata acquisition from sensor to microprocessor or computational systemand then to and end device. Combinations of different type sensors mayalso be used.

Sensors typically require some sort of power source. Energy sources maybe on board such as power or ground planes or it may be a battery basedsource. Energy harvesting techniques such photovoltaic or thermoelectricenergy harvesting techniques may be used. Others techniques known tothose skilled in the art may also be used.

In embodiments of the invention, the monitoring may be done continuouslyor periodically depending on the context of the monitored device anduser operable options, or design options.

In embodiments of the invention, the traces may be constructed of anyelectrically conductive material. Those skilled in the art willunderstand common materials used in electronics manufacturing process.These materials may include, for example, copper, silver, gold, nickel,aluminum, palladium or alloys of metals. Other conductive materials mayalso be used. Depending on the expected environment for the productincorporating an embodiment of the invention, different of theconducting metals may be preferred. Metals or alloys resistive tocorrosion may be preferred to copper's lower price point and readyavailability in corrosive environments, for example. As those skilled inthe art will understand, copper is subject to rapid corrosion in thepresence of chloride ions, but gold is not. In such an environment, goldwould be preferred so that the traces do not undergo the same corrosiveeffect as the device being monitored. Corrosion of a trace material mayalter the electrical characteristics in the same way that the productbeing sensed is altered. Those skilled in the art will understand thepreferred materials for intended atmospheres.

As is understood from this description of the preferred embodiments, nolimitation on the ways in which the conductive traces in intended. Asnoted, the embodiments of the invention may be either on the circuitboard or on the circuit. Traces employed by embodiments of thisinvention need not have any specific shape or be located in anyparticular place. It is understood, however, that the traces should notbe located in a location that negatively impacts the desired operationof the device being monitored.

As is understood from this description of the embodiments, no limitationon the connection of the sensor traces to a monitoring circuit isintended. Both on board and on circuit implementation of the inventioncontemplate that the implementation is underneath components, either onthe underside of the component itself or on the circuit board under thecomponent. An example of connections between the traces and the monitorare electrical connections such as leads, solder bumps, and pads on thecomponent. Those skilled in the art will understand the various methodsof electrically connecting different things. For instance, one method ofmaking the connections on an integrated circuit is to use otherwiseunused connections between the component and the circuit board. Thoseskilled in the art will understand that various component packages, suchas Dual Inline Packages (DIP), Small Outline IC packages (SOIC), BallGrid Arrays (BGA) packages, Land Grid Array (LGA) packages, flip chips,and other packaging technologies will have more connections (e.g. leads,wire bonds, pads, balls, solder joints) to the circuit board than thedevices requires. Typically, these connections are usually soldered butare electrically disconnected from the device within the component andthe pad on the circuit board. These non-connected connections, orfloating connections, may be used by embodiments of the inventionwithout impacting the component function. For instance, in the oncircuit method of the invention, the sensor traces can be convenientlyconnected to these connections on the device and then the correspondingconnection on the circuit board may be connected to the monitoringcircuit. In the on board embodiment of the invention, these pads mayserve as useful connection points.

In embodiments of the invention, the unused connections may be designedby a component manufacturer to connect to a monitoring device of theinvention. Such an implementation may contemplate that themicroprocessor on the board may contain the monitoring circuit. Such anembodiment would keep the sensors and monitoring circuitry entirely onthe component, as opposed to using an unmodified component where traceshave to connect down to the board and to additional circuitry.

Monitoring circuitry pursuant to embodiments of the invention and withunderstanding of what is disclosed here can be designed by one ofordinary skill in the art based on what electrical characteristics aredesired. It is understood that the measurements may be passive. Apassive monitoring would be with no voltage or current applied to thesensor traces. Such passive monitoring may be accomplished, for example,in a temperature measurement with a thermocouple arrangement ofconductors. In non-passive embodiments, for example, a small voltage,such as 3.3 volts, may be applied to a pair of sensor traces and thenthe current measured between them. It is understood that these areexamples of implementations and the monitoring circuitry is not therebylimited.

Sensors utilized by embodiments of the invention may be fabricated byany technique understood by those skilled in the art. Some examples oftechniques for making the traces are electrolysis deposition,electroplating, conductive inks or polymers, wires, foils, lithographyand photolithography.

The underside of electrical components on a board is not readilymeasurable. Providing traces on the underside of such components allowsfor such measurement. For instance, photo-reactive inorganic salts, inaddition to one or more of the methods mentioned above, may be depositedin a pattern on the underside of the circuit. The deposited metals maybe electroplated or added by any of a number of processes. An example ofa deposition process is that of U.S. Pat. No. 8,784,952, which isembodied herein for all it teaches and discloses.

As noted above, embodiments of this invention monitor the resistance intraces underneath components. When contamination is present, theresistance between traces may decrease to indicate ions in thecontamination. This may serve as an indicator that there iscontamination. If the resistance decreases below a certain value, it maytrigger an indication that the conductivity underneath a component maylead to degraded performance or failure.

The present invention provides an apparatus, system and method forgathering information and data on a timely basis regarding thereliability in and around the electronic circuit card.

Embodiments of the present invention also provide the ability totransmit or communicate the data from the traces and monitor to a devicefor computation or for decision based information communication outsidethe board or circuit. The communication system utilized may, forexample, be one of wireless (Wi-Fi, Bluetooth, cellular, nearfieldcommunication), wired (serial Ethernet or parallel connections), optical(such as fiber optic or infrared), or other communication methodunderstood by those skilled in the art of communications. All of thesemethods may be used for data acquisition from sensor to microprocessoror computational system and then to and end user or end device. It isunderstood that a combination of communication methodologies may also beused.

Data transmission is versatile and may be processed and conveyed viaBluetooth connection to an end user device, such as a laptop, smartphone or other device). And end user or computer program can furtherprocess the conveyed information to determine acceptable, orunacceptable, product conditions.

Data processing and conveyance of information may be performed onboard,but with separate circuitry to an end user device. As an example, useseparate circuitry may be used for systems that already utilize aBluetooth transceiver with sufficient bandwidth margins to allowadditional data transmission.

Large scale data storage, manipulation and analysis may be necessarydepending on the context of the contamination monitoring environment.Processed data may be produces within an integrated circuit andtransmitted to an end user device for further computation andassessment. The device may be logged into a server location that servesas a storage area for the data. Automatic uploading of data may beperformed when the device access the internet. The may be useful forenvironments that require remote access to health records and may bepart of a larger network of equipment.

A cellular transceiver may be used within the circuitry of the device.The system can communicate directly to a server and submit its ownprocessed data. This may be useful for assets that require remote accessto health records and may be part of a larger network of equipment. Thismay remove the requirement of a physical access to the system and allowfor fully remote system monitoring. It is understood that some access toa cellular signal would be required.

Discreet circuitry may be used to perform data processing, storage, andcellular transmission of data to storage. This may be useful in systemsthat are remote and already contain a means of storing and transmittingdata via a cellular connection.

A central, online, data processing and storage server may be used. Aserver location may perform data processing tasks. This may allow forthe integrated circuit to submit raw data via a cellular connection. Theend user may visualize data remotely and may perform data manipulationsconsistent with the latest research or situational developments withouthardware or firmware alterations. This methodology may be useful forremotely deployed assets that are difficult to access, and may exist aspart of a networked system.

The on board storage and data transmission may be performed outside ofthe integrated circuit.

The present invention provides an apparatus, system and method forgathering information and data on a timely basis regarding thereliability in and around the electronic circuit card assembly or systemto determine its reliability as it relates to electrochemical failuremodes or conditions that could adversely affect performance over time.

FIG. 1 shows an on circuit monitor from the underside view of a chip.For the example shown in FIG. 1, a leakage current detector is shown asan embodiment of the invention. The underside of a chip, or board, 100is shown. The chip 100 shown is roughly modeled after a QFN. A QFN is aQuad Flat No-leads package that is typically used in surface mountedelectronics designs. It is understood that other types of sensors may beused on similar designs and that other types of circuit packaging may beused. The example of FIG. 1 is not intended to limit the invention toany particular type product or monitoring.

Power connection 120 allow for power to be applied to the chip. The chip100 also shows a pair of thermal pads 150. The thermal pads 150 areshown divided in this example. There may be a singular thermal pad 150.A thermal pad 150 allows for the transfer of heat. Two non-connectedconnection (NC) 130 are shown on the chip 100. The NC 130 connectionsare not connected to a silicon die. As noted elsewhere, the presence onnon-connected connections is common practice in many chip packages. Theembodiment shown here advantages the NC connectors 150.

A sensor 140 is shown connected between and to the NC connectors 150.The sensor shown is a metal film deposited across the surface of thechip 100. As noted, this embodiment shows the metal film sensor 140deposited on the underside of the chip 100. The metal film sensor 140can be created by any appropriate method. The NC 130 pads on the chipare utilized to make electrical connections. One of the NC pads 130 willlead to a detecting circuit 160 and ground. Any current that leaksacross the chip 100 from one of the VCC 120 into the other willgenerally flow through the sensor down to the board 100 through an NCpin 130 and to the detector circuit 160. The detection circuit is thenshown connecting, in an appropriate manner as described elsewhere, withan end use device 170 for assessment and evaluation.

The computation and analysis of raw data from the sensor 140 may beperformed as appropriate at the detecting circuit 160 or at the end usedevice 170. The detecting circuit may also be on the board 100. It isalso understood that the sensor shown in FIG. 1 is that of a currentleakage detector for purposes of example. The sensor 140 may be anysuitable type of detector.

FIG. 2 show an on circuit monitor from the top side of a chip. Forpurposes of the example, this is the same sensor shown in FIG. 1. Thedashed elements in FIG. 2 are shown to indicate that they are underneaththe board 100. A chip, or board, 100 is shown with a plurality ofconnection points 110. A power supply 120 connects to a pair of thepins. The NC 130 connections are not connected to a silicon die. Asnoted elsewhere, the presence on non-connected connections is commonpractice in many chip packages. The embodiment shown here advantages theNC connectors 150.

A sensor 140 is shown connected between and to the NC connectors 150.The sensor shown is a metal film deposited across the surface of thechip 100. As noted, this embodiment shows the metal film sensor 140deposited on the underside of the chip 100. The metal film sensor 140can be created by any appropriate method. The NC 130 pads on the chipare utilized to make electrical connections. One of the NC pads 130 willlead to a detecting circuit 160 and ground. Any current that leaksacross the chip 100 from one of the VCC 120 ins to the other willgenerally flow through the sensor down to the board 100 through an NCpin 130 and to the detector circuit 160. The detection circuit is thenshown connecting, in an appropriate manner as described elsewhere, withan end use device 170 for assessment and evaluation.

A board trace 155 on the board 100 connects the sensor 140 to thedetecting circuit 160 via the non-connected connector 130. The boardtrace 155 is a standard PCB (Printed Circuit Board) trace that lead tothe detector 160 and ground. In this example, the detector 160 is anammeter. However, it is understood that any circuit or detector capableof providing current leakage detection may be used. Further, it isunderstood that any circuit may be used for detecting any othercharacteristic where appropriate.

The computation and analysis of raw data from the sensor 140 may beperformed as appropriate at the detecting circuit 160 or at the end usedevice 170. The detecting circuit may also be on the board 100. It isalso understood that the sensor shown in FIG. 1 is that of a currentleakage detector for purposes of example. The sensor 140 may be anysuitable type of detector.

The chip 100 also shows a pair of thermal pads 150. The thermal pads 150are shown divided in this example. There may be a singular thermal pad150. A thermal pad 150 allows for the transfer of heat. Twonon-connected connection (NC) 130 are shown on the chip 100.

FIG. 3 shows an on board chemical sensor. For purposes of the example inFIG. 2, the chemical sensor 340 is based on a graphene field effecttransistor (GFET). In an embodiment, the chemical sensor 340 GFET is athin and small chip that is attached to the board 300 before othercritical components are added over it. In an alternative embodiment. Thechemical sensor 340 GFET may be entirely integrated into the board 300.In both embodiments the chemical sensor 340 GFET is situated under theother components on the board 300. A plurality of pads 310 are alsoshown on the board 300. The pads 310 provide connection points for thecomponent (not shown) which will sit atop the sensor 340.

Typically, GFETs are capable to measure pH and are scalable to be ableto fit under other components on the board 300. As those skilled in theart will know, a GFET is typically made of a silicon substrate. Grapheneis the only form of carbon (or solid material) in which every atom isavailable for chemical reaction from two sides. Graphene is also azero-gap semiconductor. The chemical sensor 340 GFET is comprised of asource 341, a drain 342 and a graphene gate 345. The source 341 and thedrain 342 are shown wire bonded 335 to pads 330 on the circuit board300. The wire bonding 335 to the pads 330 may be done in conventionalfashion as understood by those skilled in the art. As the pH changesbased on chemical sensing, the current changes in a predictable manner.The current can be monitored. A reference electrode 350 connects to thechemical sensor 340 GFET. The electrode 350 provides monitoringcapability as part of a monitor 360, or separately from the monitor 360(as shown). The monitor 350 is then shown connecting, in an appropriatemanner as described elsewhere, with an end use device 370 for assessmentand evaluation.

The computation and analysis of raw data from the sensor 340 may beperformed as appropriate at the detecting circuit 160 or at the end usedevice 370. The detecting circuit may also be on the board 300. It isalso understood that the sensor shown in FIG. 3 is that of a chemicaldetector for purposes of example. Other chemical sensors may be used asappropriate for the intended use of the component and board.

FIG. 4 shows an ion selective electrode on a printed circuit board. Theunderside of a board 400 is shown. The board 400 has a plurality of pads410 which are soldered or otherwise attached to the board. A pluralityof electrical connections between pads 410 are shown. An electrode 440is also shown with an electrical connection 420 to a pad 410. Theelectrode 440 is an ISE (Ion Selective Electrode). An ISE is atransducer (or sensor) that converts the activity of a specific iondissolved in a solution into an electrical potential. The voltage isdependent on the level of ionic activity. In essence, the ISE 440changes its voltage in proportion to a substance that interacts with theelectrodes. The ISE 440 may be small ion selective electrode screenprinted on the board 400.

The electrical connections 420 show electrical connections to the chip.These electrical connections may be metallic traces. Those skilled inthe art will understand a variety of methods of providing electricalconnections on a printed circuit board. The electrical connections leadto pads on the chip that may be connected to circuitry on the board 400to enable ISE measurements. The pads 410 may also be connected to otherpads 410 that carry signals to the traces on the board 400 that lead tothe circuitry for ISE measurements. The sensing materials 445, which maybe a polymer or inorganic crystal for example, provide sensing input viathe electrical connections 420 to the electrode 440. The electrode 440may be connected to a detecting circuit via any method. Those skilled inthe art will understand how to connect the electrode 440 to thedetection circuit. The detection circuit may be connected to an end usedevice 445. It is understood that the sensing material 445 may be anymaterial capable of sensing ionic activity.

The computation and analysis of raw data from the sensor 445 andelectrode 440 may be performed as appropriate at the detecting circuit450 or at the end use device 460. The detecting circuit may also be onthe board 400. It is also understood that the sensor shown in FIG. 4 isthat of a ion selective electrode for purposes of example. The sensor445 may be any suitable type of detector.

FIG. 5 shows an on board gas sensor. The board 500 has a plurality ofpads 510. A trace 540 is on the board 500. The trace 540 may be a silverplated exposed trace. The trace 540 may be manufactured and plated in aconventional process. As shown, a portion of the trace 540 is on thesurface of the board 500 and the silver is exposed to the environment(below components). The trace 540 connects to an appropriate detectorcircuit 550. The detector circuit 550 may be enabled to detect eitherresistance changes in the trace 540 or when the circuit is in an open,or disconnected, state. As an example, sulfurous gasses (sulfur, sulfurdioxide, hydrogen sulfide, etc.) are very corrosive toward silver. Asthe silver trace corrodes, changes in the electrical resistance of thetrace 540 result. This is due to the corrosion causing the silver tochange into non-conductive silver sulfide (AgS). The trace 540 is platedto the board in a manner that makes it smaller and thinner than othersilver parts on the board 500. Because the trace 540 is thinner thanother silver plated connection on the board 500, the failure of thetrace 540 occurs faster. Failure of the trace 540 provides an indicationof possible impending degradation or failure of the components on theboard. The component would sit over the top of the trace 540.

The detector 550 may be any suitable means for determining theresistance of the trace 540. The detection circuit 550 is then shownconnecting, in an appropriate manner as described elsewhere, with an enduse device 560 for assessment and evaluation. The computation andanalysis of raw data from the sensor 540 may be performed as appropriateat the detecting circuit 550 or at the end use device 560. Further it isunderstood that other types of traces may be utilized depending on thenature of the environment involved. For instance, a chip may be intendedfor an environment that has a different type of gas and a particularmetal may corrode specifically with regard to that gas. Those skilled inthe art will understand the corrosive effects of different gasses ondifferent metals.

FIG. 6 shows an on chip gas sensor. A board, or chip, 600 is shown witha plurality of pads 610. A sensor 640 is placed on the board 600. Thesensor 640 may be on the underside of the board 600 or may be under acomponent. The sensor 640 connects to a detector 650 by any suitablemeans. The detector connects to an end use device 660 by any suitablemeans.

The sensor 640 is a metal oxide semiconductor chemiresistor. Thoseskilled in the art will understand the gas sensing techniques utilizingsuch a chemiresistor. The sensor 640 connects to two NC pads 620 on theboard. The sensor 640 is comprised of two interdigitated electrodes 641covered by a semiconductor metal oxide 642. Each of the electrodes 641connects to one of the NC pads 620. In the FIG. 6, the cross-hatchingover the electrodes 641 is used to indicate the metal oxide layer 642over the electrodes 641. The electrodes 641 and metal oxide 641 may bedeposited on the board 600 using any suitable deposition technique. Asthe metal oxide 642 corrodes, the conductivity changes and a detector650 connected to the NC pads 620 will be able to sense the change. Thedetector connects to an end use device 660.

The detector 650 may be any suitable means for determining theelectrical characteristics of the electrodes 641. The detection circuit650 is then shown connecting, in an appropriate manner as describedelsewhere, with an end use device 660 for assessment and evaluation. Thecomputation and analysis of raw data from the sensor 640 may beperformed as appropriate at the detecting circuit 650 or at the end usedevice 660. Further it is understood that many suitable types of metaloxides 642 may be utilized depending on the nature of the environmentinvolved. For instance, a chip 600 may be intended for an environmentthat has a different type of gas and a particular metal may corrodespecifically with regard to that gas. Those skilled in the art willunderstand the corrosive effects of different gasses on differentmetals.

FIG. 7a shows an impedance sensing configuration. A board 700 is shownwith an on component sensor 710, a power section 720, a datatransmission section 730, a data processing section 740 an externalsensors 750. The external sensor 760 may be a sensor that is on theboard 700. Accordingly, FIG. 7 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 710 andthe on board sensor 760 may each comprise two interdigitated electrodes.The two interdigitated electrodes provide an impedance sensingmechanism. The sensor provides information to a detector (not shown—butsimilar to FIGS. 1-6) which may then provide information to an end usedevice (not shown—but similar to FIGS. 1-6).

FIG. 7b shows typical usage of an impedance sensing configuration. Aboard 700 is shown with a component microcontroller 770. A sensor 760 isunder the microcontroller 770. The sensor connects via a connection 765to a detector circuitry (not shown) suitable for the monitoring ofchanges in impedance.

FIG. 8a shows a capacitance sensing configuration. A board 800 is shownwith an on component sensor 810, a power section 820, a datatransmission section 830, a data processing section 840 an externalsensors 850. The external sensor 860 may be a sensor that is on theboard 800. Accordingly, FIG. 8 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 810 andthe on board sensor 860 comprise a pair of parallel electrodes capableof changing capacitance. The electrodes will electrically connect adetector (not shown) in a suitable manner that is enabled to monitor thecapacitance of the electrode pair and the detector will suitably connectto an end use device (not shown).

FIG. 8b shows typical usage of capacitance sensing configuration. Aboard 800 is shown with a component microcontroller 870. A sensor 860 isunder the microcontroller 870. The sensor connects via a connection 875to a detector circuitry (not shown) suitable for monitoring of changesin capacitance.

FIG. 9a shows a voltage sensing configuration. A board 900 is shown withan on component sensor 910, a power section 920, a data transmissionsection 930, a data processing section 940 an external sensors 950. Theexternal sensor 960 may be a sensor that is on the board 900.Accordingly, FIG. 9 is showing both alternatives, the on board and theon component sensor. It is understood that the on board sensor may beused solely, the on component sensor may be used solely or both sensorsmay be used in combination. The on board sensor 960 and the on componentsensor 910 comprise a voltage source, a ground and a pair of traces.These provide a voltage sensing mechanism. As voltage across the sensorsvaries, the sensor provides information to a detector (not shown).

FIG. 9b shows typical usage of a voltage sensing configuration. A board900 is shown with an electronic switch 970. The switch 970 is shownconnected to the board 900 via the source, gate and drain of the switch970, which would be a normal installation. Traces 960 connect via aconnection 975 to a detector circuitry (not shown) suitable formonitoring voltage changes between the traces 960.

FIG. 10a shows a pressure sensing configuration. A board 1000 is shownwith an on component sensor 1010, a power section 1020, a datatransmission section 1030, a data processing section 1040 and externalsensors 1050. The external sensor 1060 may be a sensor that is on theboard 1000. Accordingly, FIG. 10 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 1010and the on board sensor 1060 comprise a barometric pressure sensor. Thesensor provides information to a detector (not shown) which may thenprovide information to an end use device (not shown).

FIG. 10b shows typical usage of a pressure sensing configuration. Aboard 1000 is shown with a photo-detector 1080. A photo-detector may besusceptible to changes in barometric pressure. The barometric pressuresensor 1060 is under the board 1000. The sensor 1060 connects via asuitable connection to a detector circuitry suitable for monitoring ofchanges in barometric pressure.

FIG. 11a shows a humidity sensing configuration. A board 1100 is shownwith an on component sensor 1110, a power section 1120, a datatransmission section 1130, a data processing section 1140 and externalsensors 1150. The external sensor 1160 may be a sensor that is on theboard 1100. Accordingly, FIG. 11 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 1110and the on board sensor 1160 comprise a humidity sensor. The sensorprovides information to a detector (not shown) which may then provideinformation to an end use device (not shown).

FIG. 11b shows typical usage of a humidity sensing configuration. Aboard 1100 is shown with a high voltage power supply 1170. A voltagesupply may be susceptible to changes in humidity. The humidity sensor1160 is on the board 1100. The sensor 1160 connects via a suitableconnection to a detector circuitry (not shown) suitable for monitoringof changes in humidity.

FIG. 12a shows an accelerometer configuration. A board 1200 is shownwith an on component sensor 1210, a power section 1220, a datatransmission section 1230, a data processing section 1240 an externalsensors 1250. The external sensor 1260 may be a sensor that is on theboard 1200. Accordingly, FIG. 12 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 1210and the on board sensor 1260 comprise an accelerometer. The sensorprovides information to a detector (not shown which may then provideinformation to an end use device (not shown).

FIG. 12b shows typical usage of an accelerometer configuration. A board1200 is shown with a crystal oscillator. A crystal oscillator may besensitive to sudden changes in speed. The accelerometer 1260 is on theboard 1200. The accelerometer 1260 connects via a suitable connection(1265) to a detector circuitry (not shown) suitable for monitoringchanges in acceleration.

FIG. 13a shows a strain-gauge sensing configuration. A board 1300 isshown with an on component sensor 1310, a power section 1320, a datatransmission section 1330, a data processing section 1340 an externalsensors 1350. The external sensor 1360 may be a sensor that is on theboard 1300. Accordingly, FIG. 13 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 1310and the on board sensor 1360 comprise an strain gauge enabled to measurestress levels. The sensor provides information to a detector (not shown)which may then provide information to an end use device (not shown).

FIG. 13b shows typical of a strain-gauge sensing configuration. A board1300 is shown with an multi-ball FPGA 1370. An FPGA may be susceptibleto physical stresses. The strain gauge 1360 connects via a suitableconnection 1365 to a detector circuitry (not shown) suitable formonitoring changes is strain.

FIG. 14a shows a temperature sensing configuration. A board 1400 isshown with an on component sensor 1410, a power section 1420, a datatransmission section 1430, a data processing section 1440 an externalsensors 1450. The external sensor 1460 may be a sensor that is on theboard 1400. Accordingly, FIG. 14 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 1410and the on board sensor 1460 comprise a thermistor enabled to measuretemperature changes. The sensor provides information to a detector (notshown) which may then provide information to an end use device (notshown).

FIG. 14b shows typical usage of a temperature sensing configuration. Aboard 1400 is shown win a MOSFET 1470. The MOSFET 1470 may besusceptible to changes in temperature. The thermistor 1460 connects viaa suitable connection 1465 to a detector (not shown) suitable formonitoring changes in temperature of the thermistor. The thermistor 1460connects to the MOSFET 1470 via thermal vias 1480 through the board. Thethermal vias 1480 allow temperature information of the MOSFET 1470 toimpact the thermistor 1460.

FIG. 15a shows a radiation sensing configuration. A board 1500 is shownwith an on component sensor 1510, a power section 1520, a datatransmission section 1530, a data processing section 1540 an externalsensors 1550. The external sensor 1560 may be a sensor that is on theboard 1500. Accordingly, FIG. 15 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 1510and the on board sensor 1560 comprise a Geiger counter circuitry module.The sensor provides information to a detector (not shown) which may thenprovide information to an end use device (not shown).

FIG. 15b shows typical usage of a radiation sensing configuration. Aboard 1500 is shown with a memory module 1570. The memory 1570 may besensitive to certain levels of radiation. The Geiger counter module 1560connects via a suitable connection 1565 to a detector (not shown)suitable for monitoring changes in radiation levels.

FIG. 16a shows a magnetic-field sensing configuration. A board 1600 isshown with an on component sensor 1610, a power section 1620, a datatransmission section 1630, a data processing section 1640 an externalsensors 1650. The external sensor 1660 may be a sensor that is on theboard 1600. Accordingly, FIG. 16 is showing both alternatives, the onboard and the on component sensor. It is understood that the on boardsensor may be used solely, the on component sensor may be used solely orboth sensors may be used in combination. The on component sensor 1610and the on board sensor 1560 comprise a magnetometer. The sensorprovides information to a detector (not shown) which may then provideinformation to an end use device (not shown).

FIG. 16b shows a typical usage of a magnetic-field sensingconfiguration. A board 1600 is shown with a pacemaker integrated chip1670. The pacemaker IC may be sensitive to magnetism. The magnetometer1660 connects via a suitable connection 1665 to a detector (not shown)suitable for monitoring changes in radiation levels.

It is understood that combinations of sensor types and arrangements maybe made on a single board or on a component. For instance, a thermistormay be used in combination with a complex capacitance/resistive sensorto provide information for multiple external influences. Where anenvironment has multiple facets, the sensors may be combined to accountfor multiple factors. Combinations of sensors allows changes in onecharacteristic to be correlated to possible changes in anothercharacteristic of the environment.

The foregoing description of the invention has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed, andother modifications and variations may be possible in light of the aboveteachings. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical application tothereby enable others skilled in the art to best utilize the inventionin various embodiments and various modifications as are suited to theparticular use contemplated. It is intended that the appended claims beconstrued to include other alternative embodiments of the inventionexcept insofar as limited by the prior art.

What is claimed is:
 1. A system for measuring electrochemicalreliability of an electronic assembly, said system comprising: two ormore electrodes integrated on an electronic assembly; a processorconnected to said two or more electrodes, wherein said processorcalculates impedance parameters and monitors changes in said impedanceparameters wherein said changes to said impedance parameters indicatesaid electrochemical reliability.
 2. The system of claim 1, wherein saidtwo or more electrodes comprise a metal film deposited on saidelectronic assembly, wherein said metal film is connected tonon-connected pads on said electronic assembly and said processor isconnected to said non-connected pads on said board.
 3. The system ofclaim 2, wherein said processor comprises a current measurement deviceand wherein said current measurement device is one of contained withinsaid processor and connected to said processor.
 4. The system of claim1, wherein said two more electrodes comprise an electrochemicalreliability measuring device.
 5. The system of claim 1, wherein said twoor more electrodes comprise an impedance sensing sensor.
 6. The systemof claim 5, wherein said impedance sensing sensor comprises one or moreinterdigitated electrodes.
 7. The system of claim 1, wherein said twomore electrodes comprise a voltage sensor.
 8. The system of claim 1,wherein said two or more electrodes comprise a thermistor.
 9. The systemof claim 1, wherein said electronic assembly comprises a top side and anunderside and wherein said two or more electrodes is located on one ofsaid topside and said underside of electronic assembly.
 10. The systemof claim 1, wherein said electronic assembly comprises a top side and anunderside and wherein said two or more electrodes is located on said topside of said electronic assembly.
 11. A method of monitoring anelectrochemical reliability of an electronic assembly, said methodcomprising: placing two or more electrodes on said electronic assembly;measuring a surface impedance parameter between said two or moreelectrodes; performing one of calculating impedance parameters andmodeling said measured impedance; determining changes in measuredsurface impedance over time, wherein said changes correlate to anelectrochemical failure of said electronic assembly; connecting amonitor to said two or more electrodes; and connecting said monitor toan end user device, wherein said end user device is enabled to indicateelectrochemical failure of said electronic assembly.
 12. The method ofclaim 11, wherein said method further comprises connecting said two ormore electrodes to non-connected pads of said electronic assembly. 13.The method of claim 11, wherein said two or more electrodes are betweena component of said electronic assembly and said printed circuit boardof said electronic assembly.
 14. The method of claim 11, wherein saidelectronic assembly comprises a top side and an underside, a componentis connected to said top side of said printed circuit board and saidstep of placing two or more electrodes on said electronic assemblycomprises placing said two or more electrodes on said underside of saidelectronic assembly.
 15. The method of claim 11, wherein said step ofplacing said two or more sensors on said electronic assembly comprisesdepositing a metal film between two non-connected pads of said printedcircuit board.
 16. The method of claim 11, wherein said impedanceparameter comprises one of a resistance parameter, a capacitanceparameter, a constant phase element parameter, and a complex impedanceparameter.